Windows 8.1 compatibility?

I’m new to this, and after poking around in the menus, I thought I’d check out the IDE integration option. However, when I tick “Visual Basic” and click next, I get a blank window that’s fairly wide but short. I can click the X to close that window. Then if I click cancel, I get another blank window of about the same height, but not so wide. I can close that window, but if I try to close the main window, I get the smaller blank window again. I have to forcefully kill the Java process. What’s going on?

VP-UML 10.2, Windows 8.1 Pro.